I am proud of the fact that I never invented weapons to kill.

What man's mind can create, man's character can control.

There is far more opportunity than there is ability.

The best thinking has been done in solitude.

The first requisite for success is the ability to apply your physical and mental energies to one problem incessantly without growing weary.

Restlessness is discontent and discontent is the first necessity of progress. Show me a thoroughly satisfied man and I will show you a failure.